Pump jack



June l0, 1941. F, A, LAGE 2,244,884

PUMP JACK Filed Feb. 2s, 1940 "IEEEIEIJEEIEEEIEE VYQZMOH Patented June10, 1941 UNITED STATES PATENT OFFICE PUMP JACK Frederick A. Lage,Gladbrook, Iowa Application February 23, 1940, Serial No. 320,464

3 Claims.

This invention relates to an improvement in pump jacks.

The object of my invention is to provide a simple, durable andinexpensive pump jack adapted to be supported in an oil-tight casing,wherein the mechanism may be operated in an oil or grease bath so as toinsure at all times proper lubrication.

A further object is to provide an improved pump jack so constructed andarranged that power may be applied to the lift rod of the pump in such amanner as to cause the lift rod to travel in a straight perpendicularline and within its guides with a minimum amount of lateral movement,whereby the guides for the lift rod may be relieved of excessive wear.

A further object of my invention is to provide in a pump jack animproved speed reducing gear mechanism wherein the noise is greatlyreduced.

A further object of my invention is to provide in a pump jack, improvedmechanism wherein the power transmitted from a shaft'rotating at acontinuous and uniform speed may be transmitted to the reciprocatinglift rod in uniform accelerated speeds.

My invention consists in the construction, arrangement and combinationof the various parts of the device, whereby the objects contemplated areattained, as hereinafter more fully set forth, pointed out in my claims,and illustrated in the accompanying drawing, in which:

Figure 1 is a vertical longitudinal sectional View of the casing showingtherein in side elevation my improved speed reducing andpowertransmitting mechanism, and the manner in which the device isapplied to the lift rod of a Dump;

Figure 2 is a plan view of the same with the cover removed;

Figure 3 is a detail sectional view taken on the line 3-3 of Figure 1;and

Figure 4 illustrates a modified form of my device.

In the drawing I have used the reference numeral I to indicate a pump ofordinary construction having at its top end a bracket II, which is alsoof ordinary construction, provided with a guide device I2 in which isslidably mounted the vertically arranged lift rod I3.

My improved jack comprises a frame or casing I4, having a bottom I5,ends I6, and side members I'I, a cover I8 being provided for the saidcasing. Rotatabiy mounted in the side members I1 is a drive shaft I9having one end projecting through one of the side members on which ismounted a belt pulley 26. The central portion of the shaft I9 isprovided with a sprocket pinion 2 I. Rotatably mounted in the oppositeend of the side members I'I is a rock shaft 22 having both of its endsextending through the members I'I, each of said ends being provided witha lever arm 23 mounted substantially in a horizontal position and havingtheir free ends terminating opposite the vertical center of the pump IU.Connected to the outer end of each of the members 23 is a lift bar 24,said lift bars being on opposite sides of the pump, having their upperends connected to the lift rod I3 by means of a bolt 25, in such amanner that as the shaft 22 is rocked, the bars 24 will be elevated andlowered, causing the lift rod I3 to be elevated and lowered.

For rocking the shaft 22 I have fixed to said shaft lever, arms 26 whichextend upwardly and outwardly from said shaft 22, the free ends of thearms 25 being provided with a shaft 21 on which is mounted eccentricallya sprocket Wheel 2'8, said sprocket wheel having a hub 29 ofconsiderable diameter, said hub being arranged concentrically with thecircumference of said sprocket, the shaft 21 passing through the hub 29in a manner clearly illustrated in Figure 1.

A chain 30 is passed over the sprockets 2| and 28.

From this arrangement it will be seen that the weight of the pLunp rodI3 will tend to move the outer ends of the arms 22 downwardly and theouter ends of the arms 26 upwardly or away from the shaft I9, so thatthe chain 39 is always maintained under tensile strain.

From the above it will be seen that if the shaft I9 is rotated, then thesprocket 2I will be rotated,l and with it the sprocket wheel l28, whichwill Vrotate about the shaft 21 as an axis; and inasmuch as the liftingstrain is always against the weight of the rod I3, it Will be seen thatthe outer end of the arms 26 will always tend to move upwardly and awayfrom the shaft I9, causing the outer ends of the arms 26 to beoscillated in the arc a-a, while the center 3I of the hub 29, and thesprocket 28 will swing in the arc b-b, so that the lift rod I3 will bereciprocated at uniform accelerated speeds. Under certain conditions theweight of the rod I3 always tends to move the outer ends of the arms 26upwardly away from the shaft I9, during one-half revolution of thesprocket 28, while the tension on one run of the chain 30 tends to pullthe arm 26 towards the shaft I9 during the other half revolution of saidsprocket 2'8.

If conditions are such that the rod I3 offers resistance on its downwardmovement, and power has to be applied to accomplish said downwardmovement, then it is necessary to provide an arcuate plate 32 to engagethe periphery of the hub 29, the center of the arc of said plate beingin the center of the shaft l, the plate 32 then serving as a bearing toprevent inward movement of the hub 29 towards the shaft I9 as power isbeing transmitted to the sprocket 28 during the downward stroke of therod I.

Under ordinary pumping conditions, however, the hub 2S seldom evertouches the said plate 32. It will readily be seen, however, that evenif the mechanism disclosed herein for operating the lift rod of a pumpmight be utilized for producing reciprocal movement to other mechanismswherein it is required that power. be transmitted to the reciprocatingelement both directions, in which case the arcuateV plate 32 would benecessary or an equivalent therefor,

In Figure 4 I have illustrated a modified form wherein the plate 32 isin the form of a roller designedl to operate about the axis iii as-acenter, so asto overcome the sliding movement between the hub 23 and theperiphery of the said roller or the outer surface of the plate 32.However, it will readily be seen that a roller takes upy consideralolyymer-e space inA the casing than would be required with an arcuate plate.For that reason the arcuate plate is prefer-ably used in pump jacks.

Thus, itA will be seen I have provided a gear mechanism which ispreferably used as a pump jack but which may also be utilized as meansof converting a constant rotary movement intoA a reciprocating movementat uniformly accelerated speeds;

One of the advantages of my device lies in the fact that the arms 23 areof considerable length and have their free' ends terminatingsubstantially in a transverse line'with the movement of the pump rod,and in View of the fact that the links'zliV are 'of considerable length,substantially very little lateral pressure is applied to that portion ofthe lift rod extending through the'guicle i 2, thereby eliminating wearon the guide and thereby eliminating the excessive amount of powerrequired tooperate the pump.

By providing a chain drive in the speed.V reduction gear mechanismbetween the rapidly moving shaft l and the rock shaft 22, I haveprovided means whereby' e. large percentage of the noise is eliminatedover` that produced by the use of spur gears used inthe ordinary speedreduction of devices of this kind, and at the same time my improveddevice also provides means whereby uniformly accelerated speeds may beimparted to the reciprocating rod similar to that produced by the crankmovement whichis quite commonly used in devices of this kind, and at thesame time eliminating the angularity of the lift links 24 which alwaysaccompanies said lift links when used in connection with a crank actionto produce this result.

I claim as my invention:

1. In a device of the class described, a frame, a drive shaft, asprocket pinion carried by said shaft, a lever arm of the rst class, asprocket wheel, a hub carried by one side of said sprocket wheel andmounted concentrically of its periphery, means rotatably andeccentrically mounting said sprocket and hub to one end of said lever, achain operatively connecting said jsprockets, arcuate means for engagingthe periphery of said hub, having its center in common with the centerof said drive shaft, means for 'connect-ing. the other end of said leverarm to a load offering resistance to the movement of said arm in eitherdirection, whereby uniform rotary movement being imparted' toY the firstsprocket will cause the load to be reciproca-ted at uniform acceleratedspeeds.

2. Ina pump jack comprising a frame, a= rock shaft mounted therein, alpair of radially and horizontally mounted lift arms, apair of rock armscarried by said rock shaft, a shaft carried by the outer ends of thelast said arms., an eccentrically mounted sprocket wheel. carried by thelast said shaft, a drive shaft, a sprocket pinion on saidy driveY shaft,a chain connecting said sprockets, lift bars carried .by the free endsof said lift arms, means connecting the ends of said lift bars to thepump rod whereby the weight of the pump rod tends to swing; the sprocketwheel away from the said sprocket pinion, wherein uniform rotarymovementl being imparted to saidsprocket pinion will cause the pump rodtobe reciprocated` at uniformly accelerated speeds.

3. In a device of the class described, a frame, a drive shaft, a drivepinion carried by said shaft, a lever arm, a. drivenzwheel, a hubcarried byone side of said driven wheel and mounted concentrically ofits periphery, means rotatabiy and eccentrically mounting said drivenwheeiand hub at one endl ofy said lever, flexible means operativelyconneeting said driving and driven wheels, a Wheel engaging. theperiphery of said hub having its centerin common with the center of Saiddrive shaft, and means for connecting the other end of. said lever to `aload offering'resistance to the movement of said; arm in eitherdirection, whereby uniform rotary movement being imparted to the firstsprocket will cause the load to` be reciprocated at uniform acceleratedspeeds..

FREDERCK A. LAGE.'

